Development of A Solid Phase Microplate Antiglobulin Test for Detection of Red Blood Cell Antibodies

Abstract

Background and objectives: A solid phase microplate antiglobulin test (SPMAT) for detection of red blood cell antibodies has been developed. Instead of agglutination, positive reactions are indicated by the adherence of sensitized red cells over the entire surface of the microplate wells, and negative reactions produce discrete buttons of red cells in the center of the wells. The performance of this method for detecting antibody to red blood cells was compared with the standard antiglobulin tube test. Materials and methods: The screening cells were fixed on the microplate wells (RBC monolayer) using a cell fixing buffer. Reaction between serum antibody and reagent red cells were detected by adding of anti-human globulin serum and anti-IgG coated indicator cells. The efficiency of the SPMAT was determined by testing with serial dilutions of various red cell antibodies and with 107 clinically significant antibodies that have been previously identified by hemagglutination tube test. The accuracy was tested against 10,995 routine blood donor sera. Results: The SMPAT gave good efficiency for detecting antibodies to red blood cell antigens. Compared with the tube test, the method was in most cases two to eight times more sensitive in antibody titration and detected 91
clinically significant antibodies where as tube test detected only 83 antibodies. The SPMAT and tube test showed an excellent agreement in 10856 (98.7%) of samples tested. Conclusions: The SPMAT provides a reliable, handy and inexpensive screening of antibodies. This method appears to be suitable to screen large series of blood donor samples.